Apparatus for heat treating metallic goods in baths



P 1 c. ALBRECHT 2,297,447

APPARATUS FOR HEAT TREATING METALLIC GOODS IN BATHS I Filed Jan. 23, 1941 2 Sheets-Sheet 1 MI I Ill 11'] INVENTOR. CAR L. ALBRECHT ATTORNEY Sept. 29, 1942. c. ALBRECHT 2,297,447

APPARATUS FOR HEAT TREATING METALLIC GOODS IN BATHS Filed Jan. 23 1941 2 Sheets-Sheet 2 INVENTOR. CARL ALBEECHT BYM ATTORNEY Patented Sept. 29, 1942 UNITED STATES PATENT OFFICE APPARATUS FOR HEAT TREATING METALLIC GOODS IN BATES Carl Albrechtrxronberg in Taunus, Germany vested in the Alien Property Custodian Application January 23, 1941, Serial No. 375,679 I In Germany February 23, 1940 1 Claim. (oi. 26H) by electrode furnaces or other conventional means. Often in such heat treating operations it is essential to protect the heat treating bath from the action of the air and for this purpose a layer of carbonaceous material, for example graphite, floating on the surface of the bath is commonly utilized. Such floating protective layers have the disadvantage, however, that the floating particles tend to adhere to the article to be heat treated when these are immersed in and removed from the heat treating bath. This can be avoided only by attempting to push back the protective layer with some manually operated tool so as to temporarily leave an area of bath surface more or less free from the floating material. Such operation is difilcult, inconvenient and hazardous to the operator and almost impossible for satisfactory accomplishment in baths of high fluidity.

An object of the present invention is an improved apparatus for use in the operation of liquid heat treating baths having protective layers of floating material thereon. A further ob- Ject is to provide means for operating baths of the above-described character in such a manner as to create and/or maintain a variable area of the heat treating bath surface substantially free from floating material. Another object is to provide means whereby the aforesaid area free of floating material may be varied in extent if desired from substantially zero to an area which, if desired, may be substantially as large as the total area of the surface of the heat treat-' ing liquid. Further objects will be apparent from the following description.

The aforesaid objects may be attained in accordance with the present invention by providing on the surface of the heat treating bath a plurality of partitions extending into the bath and rising above the surface thereof. these partling a heat treating bath with work suspended therein. The section of Figure 1 is in the plane 1-1 as shown in the plan view of the same apparatus in Figure 2. Figure 3 is a plan view of a partition element adapted to be located at the surface of a heat treating bath. Figure 4 is a plan view and in part a horizontal cross section of an apparatus according to my invention located on the surface of a liquid heat treating bath. Figure 5 is a plan view of another modification of my invention.

One method of practicing my invention is illustrated by Figures 1 and 2. A fused salt bath or other heat treating liquid I6 is maintained in the rectangular-shaped container l. The bath may be heated by means of electrodes 2 and 3 immersed in the bath, according to conventional practice. The bath surface is covered with aprotective layer of graphite t which floats on the surface of the heat treating liquid. Movable partitions l and 8 areprovided with wheels or rollers t which engage the vertically movable,

horizontally disposed tracks I0 located on either side of container I. Partitions l and 8 thus may be moved to andfrom each other in a substantially'horizontal plane by movement along tracks tions being interconnected and at least some of the partitions being movable with respect to the others in such manner thatby moving the partitions with respect to each other the area of the bath defined by said partitions may be .varied at will.

The appended drawings are plan and sectional views illustrating dilferent modes of my invenill. Tracks iii are supported by the four chains l3 located at each corner of container I. Chains i3 terminate in rings or end-links It, which are adapted to be fastened to suitable hooks or pins not shown.

In operationof the above-described apparatus,

elements I and 8 may be.moved to and from each other any desired distance so as to form between them a bath surface area of any desired size. Preferably partitions I and 8 are moved against one another before lowering them into the bath surface. Thereafter. by moving partitions I and 8 apart a bath surface area which is free from the floating graphite layer is formed. Work to be heat treated then may be dipped into the bath through this graphite-free surface and thus avoid contamination of the work by any floating particles. One method of inserting work into the bathis illustrated by Figure 1 which shows the work 4 suspended in the bath by means of .holder 5. Where the holder is of small diameter the partitions I and 8 may be moved to almost completely close the opening while the work is being treated in the bath. When the work is removed and the bath is desired to be left idle, partitions I and Q may be moved to substantially completely close the work opening In this way the bath may be protected from the air at tion. Figure 1 .is a vertical cross section showall all times except for a small area required for in sertion of the work and the movable partitions form, in effect, an entrance through the protective graphite layer, which entrance maybe opened and closed at will or adjusted to any desired width. V

In the embodiment according to Figure 3, a templet-like partition body I! is shown, having two larger recesses l5, Joined with a slot 20. The partition body I! may be operated on the guide rails II with the aid of rolls II for operation in the apparatus of Figures 1 and 2. The recesses I! and the slot 20 are constructed in such manner that the recesses allow an easy handling of the work piece through the partition bodies, while the slot has only such a breadth which enables an easy moving of the work piece supports between the recesses.

Another adaptation of my invention is illustrated by Figure 4 wherein a plurality of partitions are arranged to form a substantially rectangular opening in thegraphite layer on the bath surface and are interconnected by means of sliding connections which permit a certain.

variation of the graphite-free area on the surface of the bath. According to the specific embodiment of Figure 4, a frame is shown, consisting of four angles 22, 23, 24, 25,- arranged in a cylindrical bath container 2|. The frame may fioat on the bath surface. In the corners ofthe angle pieces, guiding elements are provided which concur with the corresponding heads or the like of the bath tank and, if necessary, are restricted to definite, for instance, only vertical movements of the frame. In the angle 23, for instance, a shoulder 25 is. arranged, connected by joint '21 to a telescopic like rod 28. The rod 24 is equipped with a spheric orv the like formed head 25 which rides between two flanges 30 along the wall of the bath container. r

The angles 22, 22, 24, and 25, are also joined by sliding or telescopic connections. For example, angle 22 is provided with a recess 3| and a connection 34 held in place by the pin 33. Pin

:4. Likewise the angle 25 is equipped with a bracket 35 which has a recess 36 with stop 31.

Stop 31 strikes against pin 38, fixed in the hollow shoulder piece 39 "which is firmly joined with a further frame angle 24. The part of the bath surface covered with graphite or the like is marked 40, while the frame encased, graphite moved so as to form a right-angled tetragon.

In the embodiment, according to Figure 5, inside of the cylindrical tank 42, a linkage 43, 44, 45, 45, with the corresponding links 41, 48, 49, 50, is provided. At the opposite links 41 and 49 telescopic like, extensible and shortenable brackets 5| are provided with heads 52 which guide the brackets along the angles 53 on the tank wall. The graphite covered part of the bath's surface is indicated at 54; the part en.-

cased by the linkage and free from graphite is designated at 55. Another position of the linkage is shown by the dotted lines, wherein a great--. er area than shown by the full-lined design is encased.

I claim: 1

A heat treating apparatus comprising a container for a heat treating liquid bath having an open top, a pair of elongated shallow partitions adapted to be situated parallel to each other at the surface of said bath, supported across the open top of said container and arranged to move to and from each other in a substantially horizontal plane, said partitions being adapted to retain solid material floating on said bath and,

I3 is fastened through the tube 34 and prevents together with the side walls of said open top,

to define a variable area of the bath surfac kept free from said floating material.

CARL ALBRECHT. 

